I think it's interesting that it isn't just a problem with American railfans. Apparently in England which is regarded as having one of the best historical preservation programs on the planet, that devotion makes people absolutely nuts. They had to call in the police for crowd control once when the Flying Scotsman was out and about. People kept crawling under moving freight trains to get closer to the ready track for pictures.
We're not an incredibly intelligent species when it really comes down to it. We can master calculus and still ignore the fact that things hundreds of times bigger than us may pose a threat.
Oh Well, Taylor